1. Field of the Invention
The present invention relates to an improved method of splicing two insulated electrical cables, and more specifically, to the splicing of electrical cables which include a conductor wrapped with an insulation composed of a cross-linked polymer.
2. Prior Techniques
Normally when two electrical cables which include a conductor wrapped with an insulation of cross-linked polyethylene are to be spliced, the insulations nearest the ends of each of the cables are first removed, usually in a bevelled fashion such that the insulation which remains near the ends will have a decreasing cross-section in a direction towards the cable ends, and the inner conductors are joined. After the conductors of the two cables are joined, for example by welding or soldering, and after a conductive layer (i.e., inner conductive layer) has been applied around the joint (at least in circumstances where the cables are high voltage types), the joint area is normally insulated by wrapping the area around the exposed conductors (and the parts of the insulation which are located near the cable ends) with several layers of an unvulcanized polyethylene-type material containing a cross-linking agent, such as di-.alpha.-cumyl peroxide or di-tert. butyl peroxide. The joint area is then subjected to a sufficiently high pressure and temperature that the layers of the tape will melt to form a homogeneous, cross-linked compound. Subsequently, and especially when the cable is a high voltage cable, a conductive layer (outer semiconductive layer) is applied over the insulation at the joint. This latter step can in fact be done either after or in connection with the formation of the homogeneous insulation covering.
The foregoing procedure has been used also when splicing cables which have cross-linked polymer insulations other than polyethylene. Normally, however, the wrapping tape which is used will be composed of the same polymer material contained in the original cable insulation.
The noted prior art procedures, however, result in waste, insofar as the insulation which was originally present at the ends of cables to be spliced is at least partially removed and discarded. This insulation must then be replaced with new insulating material once the conductors of the cables have been joined.
It is thus an object of the present invention to provide an improved splicing procedure for electrical cables which have an insulation of cross-linked polymer, and particularly an insulation of cross-linked polyethylene.